1. Field of the Invention
The present invention generally relates to the field of optical fibers, in particular to multi axis fiber optic ribbons which are configured in the shape of a cross, turbine, or pinwheel.
2. Discussion of Related Art
Optical fibers are very small diameter glass strands which are capable of transmitting an optical signal over great distances, at high speeds, and with relatively low signal loss as compared to standard wire or cable (including wire cable) networks. The use of optical fibers in today's technology has developed into many widespread areas, such as: medicine, aviation, communications, etc. Most applications of optical fibers require the individual fibers to be placed into groupings, such as in fiber optic cables.
There are many ways to manufacture and configure fiber optic cables. One of the most common forms is the use of fiber optic ribbons. A fiber optic ribbon is created when several individually insulated fibers are aligned side-by-side and then covered with a protective coating. This results in a flat fiber optic ribbon bundle (as opposed to a circular or round fiber optic tube bundle or loose wrapped bundle) which has the optical fibers held in positions parallel to each other in the same plane.
However, even though the use of the fiber optic ribbon is one of the most common ways optical fibers are employed in cables, its use is not without its problems. For example, when a cable or buffer tube requires a large number of individual fibers, the use of a ribbon structure is not very efficient. This is primarily because the ribbons are flat, while the tubes are round, thus leaving wasted space between the center of the ribbons and the inner edges of the buffer tube or cable. This can be seen in FIG. 7, which shows a typical fiber optic cable assembly 50 as known in the prior art which uses a stack of flat ribbons 54. This Figure clearly shows the wasted space 53 between the ribbon stack 54 and the inner wall 52 of the buffer tube/outer jacket 51. Further, when a large number of ribbons are in a tube, accessing any one, or any number, of fibers within the tube may be difficult, particularly those fibers located at the center of a ribbon stack. Finally, with fiber optic ribbons having a high fiber count (resulting in a wider ribbon) a significant amount of residual twist exists in the ribbon from the manufacturing process. This residual twist can make it difficult to splice fiber ribbons or maximize ribbon count in any one buffer tube or cable.